Net Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2015

Earnings Per Share [Abstract]

Summary of net earnings per share

Net earnings per share were computed as follows:

	Three months ended   March 31,
	2015		2014
	(in millions, except per share amounts)
Net earnings attributable to common stockholders	$	230.6	$	708.5
Basic earnings per common share:
Weighted-average common shares outstanding	47.9		54.8
Net earnings attributable to common stockholders	$	4.81	$	12.94
Diluted earnings per common share:
Weighted-average common shares outstanding	47.9		54.8
Dilutive common shares—stock options	0.2		0.1
Diluted weighted-average shares outstanding	48.1		54.9
Net earnings attributable to common stockholders	$	4.79	$	12.90